netfo entfo ntefo tnefo etnfo tenfo nefto enfto nfeto fneto efnto fento ntfeo tnfeo nfteo fnteo tfneo ftneo etfno tefno eftno fetno tfeno fteno netof entof nteof tneof etnof tenof neotf enotf noetf onetf eontf oentf ntoef tnoef notef ontef tonef otnef etonf teonf eotnf oetnf toenf otenf nefot enfot nfeot fneot efnot fenot neoft enoft noeft oneft eonft oenft nfoet fnoet nofet onfet fonet ofnet efont feont eofnt oefnt foent ofent ntfoe tnfoe nftoe fntoe tfnoe ftnoe ntofe tnofe notfe ontfe tonfe otnfe nfote fnote nofte onfte fonte ofnte tfone ftone tofne otfne fotne oftne etfon tefon efton feton tfeon fteon etofn teofn eotfn oetfn toefn otefn efotn feotn eoftn oeftn foetn ofetn tfoen ftoen tofen otfen foten often
Note: these 'words' (valid or invalid) are all the permutations of the word netfo. These words are obtained by scrambling the letters in netfo.